Improvement in steam-pumps



'PATENT OFFICE.

EBENEZER HILL', JR., 0F souTH NORWALK, CONNECTICUT.

IMPROVEMENT lN STEAl-V-I-PUMPS.

specification forming part of Letters Patent No. 174,955, dated March 21, 1876; appuie-:aibn inea February 15, 1876.

panying drawings, and to the letters of reference marked thereon, which form a part of this specification. i

This invention relates to that class of pnmp` ing engines known to the art as compound or differential cylinderpumps; and my invention consists in arranging within the main cylinder of a double-acting pump an auxiliary cylinder-piston of novel construction, in which the ports or conduits are so located in the main cylinder, as Well as in the auxiliary cylinder, as to register at a certain point of its stroke, due regard being had to the stroke of the operating-engine and the cut-oft' of the steam, whereby the power exerted on the piston of the steam-engine at the termination of its stroke is lessened, and particularly when working expansively, and, asis well known, the power of which is considerably reduced at the end of its stroke, which will be more fully hereinafter explained. It also consists in providing a pump with a piston within the the auxiliary cylinder, and its peculiar `ar rangement of induction and eduction valves kand ports, whereby with a uniform expenditure of power will produce a higher pressure of water at'the end of the stroke of the pump than at the beginning. Ina special .manner is this useful when a cutoff valve vis applied to the driving-engine.

Referring to the .accompanying drawing, which represents a longitudinal vertical section of a double-acting pump, the valves shown being common clack-valves, although others may be employed, .if desired- 111 theI drawing, A is the main cylinder of a double-acting p ump, S S', and R and R are suction and discharge valves within the cylinder A. C is the auxiliary cylinder, which is made to fit in the cylinder A by turning and packing in the manner of a piston., This cylinder C is also bored out in the usual manner, and has tted within it a piston, E, which is attached to its operating piston-rod F, which passes through the cylinder-head of C, and also of cylinder A, and is connected to any suitable power for operatin g the pump, generally to the steam-piston of a direct-acting engine. The Cylinder C hns induction and eduction ports D D and l) D at each end, registering with ports P P and P' P longitudinally arranged in cylinder A.

1t will be observed that these ports extend into the cylinder beyond the clack-valve ports, the purpose of which is to form a communication with the ports of cylinder C before said cylinder reaches the end of itsrstroke, thus avoiding any sudden jar or thump of the working parts on relieving the pump of its load.

The operation of myimproved pump is as follows: The cylinders A and C are well charged with water. The power being applied to move piston E by means of pistonrod F in the direction of the arrow, the action will be to cause piston E to press upon the water in cylinder C, which has been supplied through the auxiliary valve V. Thus, during'the main portion of the stroke, no opening is provided for the water to escape from cylinder G, so the water becomes practically a solid body, and forming a piston, moving the whole of the cylinder C forward by the power of piston E, cylinder O becoming a piston for cylinder A. On reaching ports P a quantity of water is discharged, due to the extended diameter of C. This action will continue until the pprt B of cylinder C has passed the ports P, and the ports D of Cylinder C will register and communicate With said ports P of cylinder A. Cylinder C will then cease to move, and piston E continuing its motion within it will discharge the water due to the area of F. However, it will be observed that the internal diameter of O is less than the internal diameter of A; hence the piston E encounters less resistance to its movement than when moving the whole cylinder C. Thus it will be seen that should the steam be cut 0E at the point where ports DA water fills the cylinder G behind the piston E, when the return stroke is the saine as the ad- Vance.

It will be seen from the foregoing that a greater water-pressure takes place at the end of the stroke than at the beginning, thus fully filling the duty required when used for forcepumps or air-compressors.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, iis- 1. The combination of auxiliary piston-cylinder C, piston E, main cylinder A, valve V, all (3o-operating to produce the result substantially as described.

EBENEZER HILL, JR. Witnesses:

C. H. DIsBRoW, 0. T. EARLE. 

